# File lib/facter/util/ip.rb, line 328
  def self.get_network_value(interface)
    require 'ipaddr'

    ipaddress = get_interface_value(interface, "ipaddress")
    netmask = get_interface_value(interface, "netmask")

    if ipaddress && netmask
      ip = IPAddr.new(ipaddress, Socket::AF_INET)
      subnet = IPAddr.new(netmask, Socket::AF_INET)
      network = ip.mask(subnet.to_s).to_s
    end
  end